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Commit 4434ade8 authored by Krzysztof Foltman's avatar Krzysztof Foltman Committed by Takashi Iwai
Browse files

ALSA: usb-audio: add support for Akai MPD16 



The decoding/encoding is based on own reverse-engineering. Both control and
data ports are handled. Writing to control port supports SysEx events only,
as this is the only type of messages that MPD16 recognizes.

Signed-off-by: default avatarKrzysztof Foltman <wdev@foltman.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent ead4046b

sound/usb/midi.c

+110 −0
Original line number Diff line number Diff line
@@ -644,6 +644,105 @@ static struct usb_protocol_ops snd_usbmidi_cme_ops = { 
	.output_packet = snd_usbmidi_output_standard_packet,

};



/*

 * AKAI MPD16 protocol:

 *

 * For control port (endpoint 1):

 * ==============================

 * One or more chunks consisting of first byte of (0x10 | msg_len) and then a

 * SysEx message (msg_len=9 bytes long).

 *

 * For data port (endpoint 2):

 * ===========================

 * One or more chunks consisting of first byte of (0x20 | msg_len) and then a

 * MIDI message (msg_len bytes long)

 *

 * Messages sent: Active Sense, Note On, Poly Pressure, Control Change.

 */

static void snd_usbmidi_akai_input(struct snd_usb_midi_in_endpoint *ep,

				   uint8_t *buffer, int buffer_length)

{

	unsigned int pos = 0;

	unsigned int len = (unsigned int)buffer_length;

	while (pos < len) {

		unsigned int port = (buffer[pos] >> 4) - 1;

		unsigned int msg_len = buffer[pos] & 0x0f;

		pos++;

		if (pos + msg_len <= len && port < 2)

			snd_usbmidi_input_data(ep, 0, &buffer[pos], msg_len);

		pos += msg_len;

	}

}



#define MAX_AKAI_SYSEX_LEN 9



static void snd_usbmidi_akai_output(struct snd_usb_midi_out_endpoint *ep,

				    struct urb *urb)

{

	uint8_t *msg;

	int pos, end, count, buf_end;

	uint8_t tmp[MAX_AKAI_SYSEX_LEN];

	struct snd_rawmidi_substream *substream = ep->ports[0].substream;



	if (!ep->ports[0].active)

		return;



	msg = urb->transfer_buffer + urb->transfer_buffer_length;

	buf_end = ep->max_transfer - MAX_AKAI_SYSEX_LEN - 1;



	/* only try adding more data when there's space for at least 1 SysEx */

	while (urb->transfer_buffer_length < buf_end) {

		count = snd_rawmidi_transmit_peek(substream,

						  tmp, MAX_AKAI_SYSEX_LEN);

		if (!count) {

			ep->ports[0].active = 0;

			return;

		}

		/* try to skip non-SysEx data */

		for (pos = 0; pos < count && tmp[pos] != 0xF0; pos++)

			;



		if (pos > 0) {

			snd_rawmidi_transmit_ack(substream, pos);

			continue;

		}



		/* look for the start or end marker */

		for (end = 1; end < count && tmp[end] < 0xF0; end++)

			;



		/* next SysEx started before the end of current one */

		if (end < count && tmp[end] == 0xF0) {

			/* it's incomplete - drop it */

			snd_rawmidi_transmit_ack(substream, end);

			continue;

		}

		/* SysEx complete */

		if (end < count && tmp[end] == 0xF7) {

			/* queue it, ack it, and get the next one */

			count = end + 1;

			msg[0] = 0x10 | count;

			memcpy(&msg[1], tmp, count);

			snd_rawmidi_transmit_ack(substream, count);

			urb->transfer_buffer_length += count + 1;

			msg += count + 1;

			continue;

		}

		/* less than 9 bytes and no end byte - wait for more */

		if (count < MAX_AKAI_SYSEX_LEN) {

			ep->ports[0].active = 0;

			return;

		}

		/* 9 bytes and no end marker in sight - malformed, skip it */

		snd_rawmidi_transmit_ack(substream, count);

	}

}



static struct usb_protocol_ops snd_usbmidi_akai_ops = {

	.input = snd_usbmidi_akai_input,

	.output = snd_usbmidi_akai_output,

};



/*

 * Novation USB MIDI protocol: number of data bytes is in the first byte

 * (when receiving) (+1!) or in the second byte (when sending); data begins
@@ -1434,6 +1533,11 @@ static struct port_info { 
	EXTERNAL_PORT(0x086a, 0x0001, 8, "%s Broadcast"),

	EXTERNAL_PORT(0x086a, 0x0002, 8, "%s Broadcast"),

	EXTERNAL_PORT(0x086a, 0x0003, 4, "%s Broadcast"),

	/* Akai MPD16 */

	CONTROL_PORT(0x09e8, 0x0062, 0, "%s Control"),

	PORT_INFO(0x09e8, 0x0062, 1, "%s MIDI", 0,

		SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |

		SNDRV_SEQ_PORT_TYPE_HARDWARE),

	/* Access Music Virus TI */

	EXTERNAL_PORT(0x133e, 0x0815, 0, "%s MIDI"),

	PORT_INFO(0x133e, 0x0815, 1, "%s Synth", 0,
@@ -2035,6 +2139,12 @@ int snd_usbmidi_create(struct snd_card *card, 
		umidi->usb_protocol_ops = &snd_usbmidi_cme_ops;

		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);

		break;

	case QUIRK_MIDI_AKAI:

		umidi->usb_protocol_ops = &snd_usbmidi_akai_ops;

		err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);

		/* endpoint 1 is input-only */

		endpoints[1].out_cables = 0;

		break;

	default:

		snd_printd(KERN_ERR "invalid quirk type %d\n", quirk->type);

		err = -ENXIO;

sound/usb/midi.h

+2 −0
Original line number Diff line number Diff line
@@ -37,6 +37,8 @@ struct snd_usb_midi_endpoint_info { 


/* for QUIRK_MIDI_CME, data is NULL */



/* for QUIRK_MIDI_AKAI, data is NULL */



int snd_usbmidi_create(struct snd_card *card,

		       struct usb_interface *iface,

		       struct list_head *midi_list,

sound/usb/quirks-table.h

+11 −0
Original line number Diff line number Diff line
@@ -1973,6 +1973,17 @@ YAMAHA_DEVICE(0x7010, "UB99"), 
	}

},



/* AKAI devices */

{

	USB_DEVICE(0x09e8, 0x0062),

	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {

		.vendor_name = "AKAI",

		.product_name = "MPD16",

		.ifnum = 0,

		.type = QUIRK_MIDI_AKAI,

	}

},



/* TerraTec devices */

{

	USB_DEVICE_VENDOR_SPEC(0x0ccd, 0x0012),

sound/usb/quirks.c

+1 −0
Original line number Diff line number Diff line
@@ -289,6 +289,7 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip, 
		[QUIRK_MIDI_FASTLANE] = create_any_midi_quirk,

		[QUIRK_MIDI_EMAGIC] = create_any_midi_quirk,

		[QUIRK_MIDI_CME] = create_any_midi_quirk,

		[QUIRK_MIDI_AKAI] = create_any_midi_quirk,

		[QUIRK_AUDIO_STANDARD_INTERFACE] = create_standard_audio_quirk,

		[QUIRK_AUDIO_FIXED_ENDPOINT] = create_fixed_stream_quirk,

		[QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk,

sound/usb/usbaudio.h

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ enum quirk_type { 
	QUIRK_MIDI_FASTLANE,

	QUIRK_MIDI_EMAGIC,

	QUIRK_MIDI_CME,

	QUIRK_MIDI_AKAI,

	QUIRK_MIDI_US122L,

	QUIRK_AUDIO_STANDARD_INTERFACE,

	QUIRK_AUDIO_FIXED_ENDPOINT,